Contact-slide for welding-machines



P. W. KRALL.

CONTACT SLIDE FOR WELDING MACHINES.

APPLICATION FILED DEC- 6, 191a.

1,36O,1 1 8. Patented NOV. 23, 1920.

ATTQRNJEY own-so STATES PETER W. KRALL, 0F, CLEVELAND, OHIO;

CONTACT-SLIDE FOR WELDING-MACHINES.

Specification of Letters Patent.

Patented Nov. 23, 1920'.

Application filed' December 6, 1918. Serial No. 265,520.

To all whom it may concern Be it known that 1, PETER W. KRALL, a citizen of the United States, and resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Im rovements in Contact-Slides for Welding chines; of which I hereby declare the following to be a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to a sliding contact block for the movable terminal of an A. C. electric welding transformer.

The object of the present invention is to rovide a simple, practical and efficient sliding contact block which will be self cleaning, to prevent of accumulation of burnt particles upon the guiding means of the block and which will be adapted to be readifly taken apart for cleaning the bearing suraces.

It is also an object of the invention to.-

provide means adapted to produce between the parts a constant recurring movement which will maintain good bearing and contacting surfaces and thus insure conductivity and prevent turning the slidable parts when a current of high voltage is passed through the device.

With these and other objects in view, the invention consists in the construction and novel combination of parts hereinafter'fully described, illiistrated in the accompanying drawings and pointed out in the claims hereto appended, it being understood that various chan es in the form, proportion, size and minor etails of construction, within the S00 e of the appended claims, may be resorte spirit of the invention or sacrificing any of I the advantages thereof.

to without departing from the faces A A which extend upwardly and inwardly from the side faces of the base or member A and terminate short of the center thereof. The slidable top member or block C is provided at the bottom with inclined faces C extending upwardly and outwardly from opposite sides of the center of the top block or member to the side faces thereof. The inclined faces'B' of the base or member and the inclined faces C of the top block or member diverge and receive between them the side blocks or members B which are tapered or wed shaped to present lower inclined faces and upper inclined faces B to contact with the inclined faces of the top block or member and the base block or member.

The side blocks or members 1) are yieldably maintained in contact with the inclined faces of the slidable top block and the base block or member by means of springs E mounted'upon rods or bolts-D piercing the side blocks horizontally e ui-distant of the base block and the slidab e top block and having a slidable fit to enable the springs E to force the side blocks or members in-. wardly. The rods or bolts are provided at their outer ends with nuts E preferably arranged in pairs and adapted to enable the tension of the springs to be readily adjusted to maintain the desired contact between the inclined faces of the top base and side blocks.

The springs maintain a constant frictional contact between the inclined faces and prevent the accumulation of burnt particles and the device operates as a good conductor for the electric current.

The lower block or base, which is stationary, is secured by screws F to the pole piece G and a cooling current of water is passed through the looped opening H in the stationary base block or member.

The slidable upper block or member C has alimited sliding movement upon the inclined upper surfaces D of the side blocks or members B, B and this movement produces the perfect bearing surfaces without air spaces, and does not interfere with the flow of the electric current through the device, and the device permits a current to flow through it without forming an arc and without turning the parts and welding them together. The constant movement of the parts on each other will wear the bearing surfaces smooth and maintain perfect contact between the blocks or members.

In order to limit the movement of the slidable top block or member independently of the side blocks or members, the top block or member, which is slightly longer than the side blocks or members, is provided at its ends with marginal flanges or plates K, K detachably secured to the top block or member by any suitable means and projecting below the inclined upper faces of the side blocks and adapted to engage the same. By this construction, the top; block or member, which is secured to the terminal G by the screws F, and which is actuated by the terminal in the movement thereof, is adapted to slide independently of the side blocks or members until one of the flanges K engages the adjacent ends of the side blocks or members and a continued movement of the terminal G will cause a movement of the side blocks or members by reason of the latter being engaged by the said flange K. A reverse movement of the terminal G will actuate the top block or member and move the same independently of the side blocks or members until the other flange K engages the side blocks or members which will then be actuated. This produces a sliding contact at the upper and lower faces of the side blocks or members and the expansion and contraction of the parts will also result in an inward and outward movement of the side. blocks and members, which will assist in maintaining the surfaces smooth and in preserving a proper contact between the blocks or members.

A plate L depends from the top block or member and is recessed or cut away to form the oppositely inclined lower edges L which conform to the configuration of the upper inclined faces of the base block or member to enable the said plate L to act as a combined dirt excluding plate and scraper. The

plate L which is provided at the top at op-' posite sides with projecting ears L", is pivoted at L to the slidable top block or member and the said plate is adapted to sweep or scrape the upper inclined faces of the base block or member and maintain the same clean and prevent the accumulation of burnt material and dust upon such bearing surfaces. Grease cups M are shown in the side blocks or members for lubricating the hearing surfaces through the channels N, N and other channels P, P conduct the overflow to the rear of the device to prevent the lubricant from coming in contact with the coils of the transformer. The inner edges or faces of the side blocks or members and the central portions of the top and base blocks or, members define a rectangular opening 0 and this spacing of the parts at the center prevents the same from interfering with the arrangement of the bolts or rodls and also assists in keeping the parts coo All of the bearing surfaces of the blocks or members are preferably planed and rubbed until perfect contact is obtained before the device is installed in the electric welding transformer R partiall indicated in Fig. 4 of the drawings. he electric current will at all times pass through the device and will not be impeded by the slidable character of the members.

Having described the invention what I claim as new and desire to secure by Letters Patent is:

1. In a slide block for use in an electric welding machine a stationary member having longitudinal bearing surfaces, an upper member and side members, said upper member having a limited sliding movement, upon said side members, and said side members slidingly movable upon said stationary member.

2. In a slide block for an electric welding machine, a lower stationar member, an upper member, and intermediate side members said upper member having a limited sliding movement upon said side members, and said side members having a sliding movement upon said lower member, said upper members supported upon said side members, and resilient means for connecting said side members together.

3. In a slide block for an electric welding machine, a lower stationary member, provided with a. water passage, side members provided with lubrication passages and slidingly movable thereon, an upper member slidingly movable upon said side members, and stop means on said side members for limiting the movements of said upper member.

4. A sliding block for electric welding machines including a stationary base member provided with oppositely inclined upper faces, an upper slidable member having oppositely inclined faces at the bottom and side members presenting inclined upper and lower bearing faces to the said inclined faces of the top and base members.

5. A sliding block for electric welding machines including a stationary base member provided with oppositely inclined upper faces, an upper slidable member having oppositely inclined faces at the bottom and side members presenting inclined upper and lower bearing faces to the said inclined In testimony whereof, I hereunto set my faces of the 'top and base members, and hand this 18, day of November, 1918.

means for maintaining the said inclined faces in yieldable contact and for causing PETER KRALL' 6 a relative movement between the top mem- I In presence ofber and the side members, and also between S. W. 'SANGSTE the side members and the bottommember. -WM. M. Mormon. 

